update_subscription

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden for behavioral disclosure. 'Update a subscription' implies a mutation operation but reveals nothing about permissions needed, whether changes are reversible, rate limits, error conditions, or what happens to unspecified subscription attributes. This leaves critical behavioral aspects undocumented.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise at just three words, with zero wasted language. While this brevity comes at the cost of informativeness, it's structurally efficient and front-loaded, earning full marks for conciseness.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutation tool with no annotations and no output schema, the description is severely inadequate. It doesn't explain what 'updating' entails, what values can be changed, what the expected outcome is, or how it differs from sibling operations. Given the complexity of subscription management, this leaves too many contextual gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, with all three parameters ('token', 'amount', 'frequency') documented in the schema. The description adds no additional meaning about parameters beyond what the schema already provides, so it meets the baseline score of 3 where the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Update a subscription' is essentially a tautology that restates the tool name 'update_subscription' without providing any meaningful elaboration. It doesn't specify what aspects of a subscription can be updated or what resources are involved, making it minimally informative beyond the obvious.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. With sibling tools like 'cancel_subscription', 'create_payment', and 'refund_payment' available, there's no indication of when subscription updates are appropriate versus cancellation or payment modifications, leaving the agent without contextual direction.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.